The Salk Institute maintains a central facility for the preparation of media and sterile solutions used by investigators. The facility has equipment for preparing, sterilizing and dispensing media and solutions. The media preparation facility provides a reliable supply of media, buffers and solutions, and prepares specialized media and solutions that are expensive or impractical to purchase commercially. The Facility also provides specialized services such as preparation of agar plates for culture of bacteria and C. elegans. Liquid nitrogen and carbon dioxide are dispensed from central sources for us in 15 liquid nitrogen storage tanks and 110 tissue culture incubators in Cancer Center laboratories. These compressed gases are shared by all investigators.